A standard motor-vehicle door latch mounted on an outer door edge has latching mechanism comprised mainly of a fork that can in a locked position engage around a jamb-mounted bolt and hold the door closed, and that can in an unlocked position release this bolt. The latching mechanism also normally has a pawl that is used to block the fork in the locked position, the fork being spring-loaded to move into the unlocked position when released by this pawl.
Typically the fork has an outer arm and an inner arm forming a retaining seat between themselves. The fork is oriented in a vertical plane with the two arms pointing down and the seat also open down. The pivot axis is of course above the seat and between an upward extension of the arms so that the fork pivots between a downwardly and outwardly open position when open and a downwardly and inwardly open position when closed. In the locked position it engages downward over the bolt, normally with same fitting solidly in the seat between the fork arms. The latch is enclosed in a housing formed with a notch at which the seat between the fork arms is exposed in all positions, and the bolt has an enlarged head wider than the notch. In the locked position outward movement of the bolt is limited by the outer arm of the fork, upward movement by engagement with the seat of the fork, inward movement by the interfit of the door and post, and downward movement by the lower edge of the notch of the latch housing.
It is therefore standard to fit the door to the vehicle such that the bolt bears upward with some slight force on the fork in the locked position. Thus elastic deformation of the parts constitutes a prestressing action keeping the bolt snug in the latch when the door is locked. Even if the bolt is a little high, this only makes it a particularly tight fit, but still lets the door close and latch properly. When a little low. However, the bolt will not contact the downwardly directed surface of the seat between the fork arms and will likely move vertically somewhat as the car hits bumps. The resultant rattel not only is annoying, but can be indicative of considerable wear taking place.